Switching apparatus



5 Sheets-Sheet l H. H. RUGG SWITCHING APPARATUS Filed June 28, 1940 Oct.' 6,

INVNTOR Haro/d H ATTOR Y Oct. s, 3942. H, H RUGG 2,298,234

SWITCHING APPARATUS Filed June 28. 1940 3 Sheets-Sheet 2 @5. jig@ wnTNEssEs: m' anx/Emma Ham/a7 /vf 19A/gg.

A ATTO Oct. 6, 1942.

H. H. RuG 2,298,234

SWITCHING APPARATUS Filed June 28, 1940 3 Sheets-Sheet 3 ATTORN -atentecl Oct. 6, 1942 UNITED STATES PATENT OFFICE sWrrcHING APPARATUS Pennsylvania Application June 28, 1940, Serial No. 342,899

8 Claims.

My invention relates, generally, to switching apparatus and it has reference in particular to a key interlock system for providing a predetermined sequence of operations in switching apparatus of the enclosed type usually embodying a circuit breaker and isolating disconnect switches.

Generally stated, it is an object of my invention to provide an improved key interlock system for a switch operating mechanism that is simple and inexpensive to manufacture and which is highly effective in operation.

More specifically, it is an object of my invention to provide for locking a relatively high speed driving member of a switch operating mechanism by means of key operated lock devices so as to prevent operation of the switch operating mechanism until an associated circuit breaker has been opened and the circuit breaker enclosure has been closed.

Another `object of my invention is to provide for preventing rotation of a driving shaft in a switch operating mechanism by means of a stop member actuated by the driving shaft, a guard member actuated by a driven shaft and a plurality of key operated lock devices actuable to interfere with the stop member and the guard member, and so associating the stop member, guard member and lock devices that the driving shaft cannot be rotated until the guard member is free of the look devices.

A further object of my invention is to provide for preventing the operation of a switch device actuated through a worm gear reduction drive having a relatively high speed driving shaft and a relatively low speed driven shaft by utilizing a plurality of key-operated lock devices for preventing rotation of the driving shaft except under predetermined conditions and preventing the operation of at least one of the lock devices until the switch device has been operated to a predetermined position.

In accordance with my invention, a simple and eiiicient key interlock system may be provided for switching apparatus comprising a circuit breaker, an associated switch device or disconnect switch and a circuit breaker enclosure, by providing the relatively high speed driving shaft, of a gear reduction unit for operating the disconnect switch, with a projecting stop member, and utilizing key-operated lock devices having bolt members actuable to interfere with the stop member. One of the lock devices may be operated only by a key normally positioned in a lock on the circuit breaker operating mechanism, and

removable therefrom only when the circuit breaker is in the open position. The other of the lock devices normally holds a key removable only when the bolt member thereof is actuated to interfere with the stop member for operating a lock device on a door of the circuit breaker enclosure. A suitable guard or indicating member may be provided to indicate the position of the switch, and may be interposed between the lock devices and the driving shaft to prevent operation of the lock devices to permit the removal of the keys therefrom except when the switch is in predetermined positions. The guard member, stop member and lock devices may be so related that the driving shaft cannot be rotated until the guard member is free of interference from the lock devices.

For a more complete understanding of the nature and scope of my invention, reference may be had to the following detailed description and the accompanying drawings, in which Figure 1 is an enlarged broken outside View of a switch enclosure showing a side elevational View of a switch operating mechanism embodying the principal features of my invention;

Fig. 2 is an enlarged rear elevational View of the switch operating mechanism of Fig. 1 with the rear panel lof the enclosure removed;

Fig. 3 is a diagrammatic View of a switching system embodying the principal features of the invention;

Fig. 4 shows diagrammatic front views of a switch cubicle for switching apparatus embodying the principal features of the invention;

Fig. 5 shows a diagrammatic rear view of -the cubicle of Fig. 4;

Fig. 6 is a rear elevational view of a switch cubicle embcdyingthe invention;

Fig. 'l' is a side elevational view partly in section of the cubicle of Fig. 6; and

Fig. 8 is a front elevational view of the cubicle of Figs. 6 and 7.

Referring to Figs. l and 2 of the drawings, the

reference numeral Il] may denote generally a switch operating mechanism of any suitable type such as may be used to operate a switch device `such as a plurality of disconnect switches associated with circuit breakers in a switching system. The switch operating mechanism lil may comprise a gear housing l2, vin which may be mounted a relatively high speed driving shaft I4 disposed in geared relation with a relatively low speed driven shaft I6 for actuating the switch device `or disconnect switches (not shown). The switch operating mechanism maybe supported in any suitable manner, being for example, se-

cured by means of bolts |8 which pass through flanges I9 on the gear housing I2 to a bracket 28 which may be supported in any suitable manner within the switch enclosure, being for eX- ample, secured to the side wall 22 just within the rear panel or door 24 of the switch enclosure.

In order to provide a simple and effective interlock between the switch operating mechanism i3 and an associated circuit breaker and circuit breaker enclosure door, means may be provided for preventing rotation of the high speed driving shaft i4, such as the elongated stop member 38 which may have notched end portions 3|. The stop member 3i] may be mounted on the driving shaft i4 in any suitable manner so as to rotate therewith and provide for preventing rotation of the driving shaft under predetermined conditions.

With a View to preventing rotation of the driving shaft I4 under predetermined conditions of the associated circuit breaker, switch, etc. suitable means, such as the key-operated lock devices 32 and 34, may be provided having bolt members 33 and 38, respectively, which may be actuated to interfere with rotation of the stop member 38 when the lock devices are operated to a position in which the operating keys may be removed therefrom. The lock devices may be positioned in any suitable manner, being, for example, secured to a support bracket 4 which may be fastened to the bracket 20.

The lock device 32 may be operated by means of a key which may be normally positioned in a lock device on the circuit breaker mechanism (not shown), and is removable therefrom only when the circuit breaker is in the open position. The lock device 34 may be actuated by a key 39, normally positioned in the lock device and removable therefrom only when the bolt member 38 has been actuated into a position where it interferes with rotation of the stop member 38. The key 39 may then be used to open the door of the circuit breaker enclosure.

In order to permit operation of the lock device 34 to remove the key therefrom only when the switch device actuatedby the switching mechanism I8 is in theropen position, suitable means such as the guard member 42 may be provided. The guard member 42 may, for example, comprise substantially an elongated angle member which may be supported for movement in the vertical direction by means of a rod 44 slidably mounted in openings 45 in the lock support bracket 48. Suitable indicia 41 and 48 may be provided on the leg 49 of the guard member 42 adjacent the door or panel 24 and viewable through an opening in the panel or door 24 to indicate the position of the switch device. The side leg 58 of the guard member 42 positioned adjacent the lock devices to interfere with their operation may be provided with spaced openings 52 and 54 to permit actuation of the bolt members 35 and 38 of the lock devices 32 and 34 to interfere with the notched end portions 3| of the stop members when the switch device is in predetermined positions, and prevent operation of the lock device 34 when the switch device is in the closed position. For example, the openings 52 and 54 may be so positioned as to receive the bolt members 35 and 38 when the guard member is actuated to its uppermostl position, and only the bolt member 36 when the guard member is in its lowest position, as shown.

In order to prevent rotation of the driving shaft i4 while the bolt members are still in a position such as to interfere with movement of the guard member 42, an elongated slot 55 may be provided in the guard member and the stop member 3i) may be so arranged that the end portions 3| project therethrough when the shaft |4 is rotated. The bolt members 35 and 38 will, therefore, have to be withdrawn clear of the openings 52 and 54 before the driving shaft I4 can be rotated to actuate the switch operating mechanism.

For the purpose of actuating the guard member 42 in accordance with the position of the switch device operated by the mechanism suitable means may be provided for operatively connecting the guard member 42 to be actuated in accordance therewith. For example, a projecting arm 55 may be provided on the driven shaft IS which is rotated through approximately one-quarter of a revolution during the operation of the mechanism. Suitable means may be provided for effecting vertical motion of the guard member 42, such as the plate member 58, which may be pivotally mounted on a xed bearing pin 68 on the gear housing I2 and connected to the guard member 42 by means of a pin B2 secured thereto. The plate member 58 may be operatively connected to the arm 56 of the shaft I6 by means such as an adjustable turnbuckle 68 which may be secured` at one end to the arm 56 by means of an eye bolt GS and connected to the plate member 58 by means of a pin 70 at the other end. When the driven shaft I6 is rotated in a clockwise direction to open the switch device, the plate member 58 rotates about the support pin 68 in a counterclockwise direction so that the guard member 42 is actuated vertically upwards.

In order to understand clearly the sequence of operations of the circuit breaker mechanism, the switch actuating mechanism and the door for the circuit breaker enclosure, reference may be made to Figs. 3, 4 and 5, which illustrate schematically, and Figs. 6, '7 and 8 which illustrate in detail a switching apparatus of the general type with which my invention is adapted to be used. The reference numerals and 'I2 may denote generally circuit breaker and disconnect switch enclosures while the reference numerals '13, 14 and 'l5 may denote, respectively, a multi-pole, circuit breaker arranged in this instance for use with a three-phase power system, and aY switch device such as, for example, a pair of gang-operated disconnect switches used to isolate the circuit breaker from the conductors 'l5 and T3. A keyoperated lock device 88 may be associated with the circuit breaker operating mechanism having a key 82 which is removable therefrom only when the circuit breaker is in the open position. Means may be provided for tripping the circuit breaker to the open position, such as the trip lever 19 shown associated with the lock device S8 and connected by means of a rod 8| to the circuit breaker mechanism 83 in Fig. 6. The door 84 of the circuit breaker enclosure 'il may be provided with an additional lock device 36 which is adapted to be operated by means of the key 39 of the lock device 34 to open the door 84 of the circuit breaker enclosure for gaining access to the circuit breaker. The key-operated lock devices 32 and 34 of Figs. l and 2 are shown in Fig. 3 `as being operatively connected with the disconnect switches 18 through the switch operating mechanism. In Fig. 7 the switches 'I4 and l5 are shown connected to the operating mechanism Il) by means of rods 85 and 89, respectively.

The sequence of operation with an interlock system of vthe type hereinbefore described is as follows. The circuit breaker 'I3 must first be opened by operating the trip lever 'I9 to release the key 82 from the circuit breaker lock device 80, and cannot be closed while the key 82 is removed. The key 82 may then be inserted in the lock device 32 as indicated by the arrows on Figs. 4 and 5 to actuate the bolt member 36 to the left from the position in which it is shown in Fig. 2, so that it no longer interferes with the stop member 38 to prevent rotation of the driving shaft I4, or movement of the guard member 42. The driving shaft I4 may then be rotated to actuate the driven shaft I6 in a direction to open the disconnect switches 'I4. In operation, the shaft I4 makes several complete revolutions in order to `operate the shaft I 6 through one-quarter turn. Actuation of the driven shaft I6 effects rotation of the plate member 58 and raises the guard member 42. When the disconnect switches 'I4 are in the open position, the openings 52 and 54 in the guard member are in alignment with the bolt members 36 and 38 of the lock devices 32 and 34, respectively, and the indicia Open is visible through the opening in the panel 24.

The lock device 34 may now be operated by means of the key 39 to actuate the bolt member 38 to the right from the position shown in Fig. 2, to a position where it may engage the notched portion 3l of the stop member 30 and prevent rotation of the driving shaft I4. The key 39 may be removed when the bolt member 38 has been thus actuated and inserted in the lock device 83 to open the door 84 of the circuit breaker enclosure, as indicated by the arrows on Figs. 4 and 5. Under these conditions, the lock device 32 may also be operated to actuate the bolt member 33 to the right to the position shown in Fig. 2 so as to prevent any operation of the driving shaft I4 to close the disconnect switches 14. The key 82 may then be removed therefrom and inserted in the lock device 80 if it is desired to operate the circuit breaker 13, while the disconnect switches 'I4 are in the open position.

To close the disconnect switches 14, the door 84 of the circuit breaker enclosure 'II must be closed and locked so that the key 38 may be removed from the lock device 86 and inserted in the lock device 34. The lock device 34 may then be operated to withdraw the bolt member 38 from interfering with the stop member 3!! and the guard member 42. 'Ihe lock device 32 may likewise be operated, after opening the circuit breaker and removing the key 82 from the lock device 80, so that the driving shaft I4 of the switch operating mechanism IIJ may be rotated to close the disconnect switches 'I4 to the closed position. In this position, the guard member 42 cccupies the position shown in Fig. 2 and the indicia Closed appears in the opening in the panel 24. The lock device 34 may be operated to lock the switches in the closed position and the key 82 used to release the breaker operating mechanism. rIhe key 39 cannot be removed from the lock device 34 while the disconnect switches are in the closed position because the guard member 42 prevents operation of the lock device 34.

Should it be desired to interlock the door or panel 24 of the switch enclosure 'I2 with the switch operating mechanism, circuit breaker and circuit breaker enclosure door, an additional lock device 88 shown in Figs. 2, 3, 5 and 8 may be provided for normally holding a key for operating a lock 9) on the switch enclosure door 24, or a double lock device could be substituted for the single lock device 34, having a single bolt member, but receptacles for two keys.

From the above description and the accompanying drawings, it will be apparent that I have provided a simple and effective interlocking systeni for a switch device which effectively locks the relatively high speed driving shaft of the gear reduction unit to which the motive force for operating the switch device is applied, se as to require a minimum of restraining force. The switch device is thus effectively prevented from being opened or closed unless the circuit breaker is open and the door of the circuit breaker enclosure cannot be opened unless the switch device is open. Furthermore, the switch device cannot be closed unless the door of the circuit breaker enclosure is first closed, whereas the circuit breaker itself may be opened at any time. In this manner, an eicient and fool-proof interlocking of the circuit breaker switch device and the door of the circuit breaker enclosure is secured, thus providing a maximum of safety to the operator. Operation of the driving shaft when the lock devices are only partially operated to the free position is effectively prevented, thus protecting the guard or indicating mechanism from excessive stresses due to improper operation of the mechanism.

Since certain changes may be made in the above description and different embodiments of :le invention may be made without departing from the spirit thereof, it is intended that all the matter contained in the above description or shown in the accompanying drawings shall be considered as illustrative and not in a limiting sense.

I claim as my invention:

l. An interlock system comprising, a driving member, a driven member associated in geared relation with the driving member, a stop member actuated by the driving member, lock means operable to limit movement of the stop member, and means operatively connected to the driven member for preventing operation of the lock means except in predetermined positions.

2. rEhe combination with a relatively high speed driving member and a relatively low speed driven member associated in geared relation therewith, of a lock device, means operatively connected to the driving member cooperative with the lock device to prevent movement of the driving member, and means operatively connected to the driven member actuable to limit he operation of the lock device under predetermined conditions.

3. The combination in an interlock system for la circuit breaker provided with a lock and a key, a disconnect switch having an operating mechanism with a driving and a driven shaft, and an enclosure for the circuit breaker having a lock device, of a lock device operable by the key of the circuit breaker lock, means operatively connected to the driving shaft adapted to interfere with a portion of the said lock device in locked position, an additional lock device normally holding a key for opening the circuit breaker enclosure having a portion for interfering with the said means to prevent rotation of the driving shaft, and additional means operatively connected to the driven shaft operable to prevent operation of the additional lock device when the switch is in the open position.

4. An interlock for a switch mechanism having a gear reduction drive mechanism with a driving and a driven shaft comprising, a member mounted on and rotatable with the driving shaft, a rst lock device having a bolt operable to interfere with the said member on the shaft and prevent rotation thereof, a second lock device having a bolt operable to interfere with the said member, and means operable in accordance with the position of the switch to interfere With operation of the lock devices to prevent operation of the switch mechanism except in predetermined switch positions, the lock devices, the said member and the said means being so associated that the said member interferes with the lock devices until the said means is free therefrom.

5. The combination with an operating mechanism having driving and driven members associated in geared relation, of means operatively connected to the driving member, a plurality of lock devices having bolt members actuable to interfere With the said means by means of keys which are removable only when the bolt members are in the actuated position, and additional means operable in accordance with the operation of the mechanism to permit the actuation of the bolt Vmember of one of the lock devices only in a predetermined operating position of the mechanism.

6. A lock system for an operating mechanism having a driving shaft and a driven shaft operable in geared relation comprising, a stop member mounted on the driving shaft and rotatable therewith, a plurality of lock devices having bolt members actuable by keys to interfere with the stop member and prevent rotation of the driving shaft, a guard member operatively connected to the driven shaft interposed between the lock devices and the driving shaft having a slot to receive the stop member, and a plurality of openings to receive the bolt members positioned to permit actuation of the bolt member only in predetermined positions of the operating mechanism, and indicia on the guard member for indicating the Operating position of the mechanism.

7. The combination in a mechanical key interlock system for a circuit breaker having a key removable only when the circuit breaker is open, a disconnect switch operating mechanism having driving and driven shafts associated in geared relation, and an enclosure for the circuit breaker having a door with a key operated lock device from which the key may be removed only when the door is locked, of a projecting stop member actuated by the driving shaft, a lock device operated by the circuit breaker key having a bolt member actuable to interfere with the stop member to prevent rotation of the driving shaft, an additional lock device having a bolt member actuable to interfere with the stop member and a key removable only when the bolt is actuated for opening the enclosure door lock device, and means actuated in accordance with the position of the switch actuating mechanism to prevent actuation of the bolt members except in predetermined positions of the operating mechanism.

8. The combination with a switch operating mechanism having a driving shaft and a driven shaft connected thereto in geared relation for operating a disconnect switch associated with an enclosed type circuit breaker having key operated lock devices for the breaker mechanism and the enclosure operable under predetermined conditions, of a projecting stop member operatively connected to the driving shaft, a key operated lock device operable by the key from the circuit breaker mechanism and having a bolt member operable to interfere with the stop member to prevent rotation of the driving shaft, an additional key operated lock device having a bolt member actuable to interfere with the stop member and a key removable only when the bolt is thus actuated for operating the enclosure lock device, and means actuated by the driven shaft operable to prevent actuation of the bolt member of the additional lock device so as to prevent removal of its key to open the enclosure except when the disconnect switch is in the open position.

HAROLD H. RUGG. 

